The present technology relates to a battery pack including a plurality of secondary batteries, and an electric power tool and an electronic apparatus that each use the battery pack.
Electronic apparatuses have been widely used, and small and light-weight secondary batteries that have ability to achieve high energy density have been developed as power sources applied to the electronic apparatuses. Applications of the secondary batteries are not limited to the electronic apparatuses described above, and it has been also considered to apply the secondary batteries to other applications such as an electric power tool.
In association with higher performance and more multi-functionality of electronic apparatuses and other apparatuses, a further increase in energy density of the secondary batteries is desired, which causes an increase in an amount of heat generated during use of the secondary batteries. Accordingly, in order to easily and safely handle the secondary batteries, a battery pack is used. The battery pack includes a plurality of secondary batteries contained in a containing member.
Various studies have been conducted on an improvement in safety of the battery pack. More specifically, a container provided to a thermal-conductivity holder contains secondary batteries (unit cells), and an endothermic agent is provided between a containing member and the secondary batteries inside the container (for example, refer to Japanese Unexamined Patent Application Publication No. 2012-119137).